Multi-perspective display of an image using illumination switching

ABSTRACT

According to one implementation, a multi-perspective image display system includes a motor configured to spin a rotor, a display screen coupled to the rotor, and a controller. The controller is configured to cause the motor to spin the display screen, using the rotor, about an axis of rotation at a spin rate, and to determine, based on the spin rate, an illumination on-time for an illumination source of the display screen. The controller is also configured to sequentially render each of multiple different perspectives of an image on the display screen during each revolution of the display screen about the axis of rotation and, concurrently with sequentially rendering each of the plurality of perspectives of the image on the display screen, to strobe the illumination source of the display screen based on the determined illumination on-time to display the multiple different perspectives of the image.

BACKGROUND

Increases in computing power have made possible the generation of richlyfeatured virtual imagery capable of simulating in-person interactivity.However, the display screens with which many modern communicationdevices are equipped are typically designed to display a two-dimensional(2D) image from a single viewing perspective. As a result, and despitetheir ability to display sharp, richly featured, high definition images,interactive group activities centered on those devices, such asmulti-player gaming, for example, tend to be less than optimallyengaging and immersive if not limited entirely.

An alternative to the conventional approach to providing 2D images is torender interactive group activities using 3D imagery. However, severalsignificant obstacles to wider use of 3D imagery in gaming andentertainment exist. For example, in order to project a 3D image,solutions often entail multiple expensive projectors, multiple sets ofaugmented reality (AR) headgear, and/or other complex display technologyis typically required to create the illusion of a real-world 3D image.Further system complications can occur if the 3D image is to be viewedfrom multiple perspectives and still maintain a desirable level ofrealism (e.g., positioning and location of users and images, timesynchronization, display performance, user comfort, environmentalrestrictions, etc.).

SUMMARY

There are provided systems and methods for displaying multipleperspectives of an image using illumination switching, substantially asshown in and/or described in connection with at least one of thefigures, and as set forth more completely in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows a diagram of an exemplary multi-perspective image displaysystem, according to one implementation;

FIG. 1B shows a diagram of an exemplary sensor network suitable for useas part of the multi-perspective image display system of FIG. 1A,according to one implementation;

FIG. 1C shows a diagram of exemplary position and/or rate (P/R) sensorssuitable for use as part of the multi-perspective image display systemof FIG. 1A, according to one implementation;

FIG. 2A shows a diagram of an exemplary multi-perspective image displaysystem, according to another implementation;

FIG. 2B shows a side view of the exemplary multi-perspective imagedisplay system shown in FIG. 2A along perspective lines 2B-2B in thatfigure, according to one implementation;

FIG. 3 shows a diagram of exemplary locations for viewing multipleperspectives of an image generated by the systems and according to themethods disclosed in the present application;

FIG. 4 shows a flowchart outlining an exemplary method for displayingmultiple perspectives of an image using illumination switching,according to one implementation;

FIG. 5A shows an exemplary timing diagram of illumination switching fordisplay of a multi-perspective image using a twisted nematic fieldeffect (TN) liquid-crystal display (LCD), according to oneimplementation;

FIG. 5B shows an exemplary timing diagram of illumination switching fordisplay of a multi-perspective image using an in-plane switching (IPS)LCD, according to one implementation; and

FIG. 6 shows a diagram illustrating the calculation of exemplary starttimes for illumination of a display as it spins, according to oneimplementation.

DETAILED DESCRIPTION

The following description contains specific information pertaining toimplementations in the present disclosure. One skilled in the art willrecognize that the present disclosure may be implemented in a mannerdifferent from that specifically discussed herein. The drawings in thepresent application and their accompanying detailed description aredirected to merely exemplary implementations. Unless noted otherwise,like or corresponding elements among the figures may be indicated bylike or corresponding reference numerals. Moreover, the drawings andillustrations in the present application are generally not to scale, andare not intended to correspond to actual relative dimensions.

The present application discloses systems and methods for displayingmultiple perspectives of a virtual image using a single display screenthat overcome the drawbacks and deficiencies in the conventional art.FIG. 1A shows a diagram of exemplary multi-perspective image displaysystem 100, according to one implementation. As shown in FIG. 1A,multi-perspective image display system 100 includes stationary base 140,and display screen 190 coupled to rotor 148 and configured to rotatewith rotor 148.

As further shown in FIG. 1A, display screen 190 includes display surface192 and computing platform 102 communicatively coupled to displaysurface 192. Computing platform 102 includes application specificintegrated circuit (ASIC) 110 (hereinafter “controller 110”) includingcentral processing unit (CPU) 112 implemented as a hardware processor,graphics processing unit (GPU) 114, and may further include digitalsignal processor (DSP) 116. Computing platform 102 also includes systemmemory 106 implemented as a non-transitory storage device storingsoftware code 108.

Base 140 includes motor 142 for rotating rotor 148 and display screen190, and motor control circuit 144 including motor control unit (MCU)146. Base 140 is situated on surface 150, which may be a floor or anyother substantially horizontal surface. In addition, FIG. 1A showshorizontal axis 152 (hereinafter also “X axis 152”) substantiallyparallel to surface 150, and vertical axis 154 (hereinafter also “Z axis154”) substantially perpendicular to surface 150. Also shown in FIG. 1Aare sensor network 120 bridging base 140 and display screen 190, andmulti-perspective image 118 displayed by display screen 190, as well asobservers 117 a and 117 b viewing respective perspectives 119 a and 119b of multi-perspective image 118.

It is noted that although FIG. 1A depicts computing platform 102 asbeing integrated with display screen 190, that representation is merelyexemplary. In other implementations, computing platform 102 may beintegrated with base 140. It is further noted that the combination ofcontroller 110, sensor network 120, and motor control circuit 144 enablethe necessary time synchronization between the revolutions per minute(rpm) of motor 142 and rotor 148, and the frame rate in frames persecond (fps) at which display screen 190 renders images.

By way of definition, as used in the present application, the terms“central processing unit” or “CPU” and “graphics processing unit” or“GPU” have their customary meaning in the art. That is to say, a CPUincludes an Arithmetic Logic Unit (ALU) for carrying out the arithmeticand logical operations of controller 110, as well as a Control Unit (CU)for retrieving programs, such as software code 108, from system memory106. A GPU is configured to reduce the processing overhead of the CPU byperforming computationally intensive graphics processing tasks.

In addition, for the purposes of the present application, the term“perspective” refers to the particular viewpoint from which an object,virtual object, or image is viewed by an observer. Referring to FIG. 1A,for example, a perspective of multi-perspective image 118 refers to thelocation of an observer of multi-perspective image 118 with respect to acircle substantially concentric with rotor 148 of multi-perspectiveimage display system 100, in a plane substantially perpendicular tovertical Z axis 154.

Furthermore, the terms “render” and “rendering” are defined to meancausing one or more images to appear on display screen 190. Thus,rendering an image may mean causing an entirely new image to appear onthe display screen, or refreshing an image previously appearing on thedisplay screen.

It is noted that although FIG. 1A shows two observers 117 a and 117 band two perspectives 119 a and 119 b of multi-perspective image 118,that representation is provided merely for conceptual clarity. Moregenerally, observers 117 a and 117 b may correspond to a singleobserver, or to more or many more than two observers who may bepositioned so as to view multi-perspective image 118 from a variety ofdifferent perspectives. For example, in some implementations, observers117 a and 117 b may be situated so as to view multi-perspective image118 from two discrete perspectives located approximately 180° apart on acircle substantially concentric with rotor 148 in a plane substantiallyperpendicular to vertical Z axis 154. However, in other implementations,observers 117 a and 117 b may be able to view multi-perspective image118 from the perspectives of other locations on such a circlesubstantially concentric with rotor 148, such as four locationsapproximately 90° apart on the circle, or twenty locations approximately18° apart, for example.

FIG. 1B shows a more detailed exemplary implementation of sensor network120, shown in FIG. 1A. As shown in FIG. 1B, sensor network 120 includesmultiple sensors and sensing modules 122 controlled by CPU 112 ofcontroller 110. According to the exemplary implementation shown in FIG.1B, sensor network 120 also includes one or more microphone(s) 124,analog-to-digital converter (ADC) 126, and localization module 128. Asfurther shown in FIG. 1B, sensors 122 of sensor network 120 may includeradio-frequency identification (RFID) reader 122 a, facial recognition(FR) module 122 b, automatic speech recognition (ASR) module 122 c,object recognition (OR) module 122 d, image sensor 122 e, and one ormore position and/or rate (P/R) sensor(s) 130.

It is noted that specific examples of P/R sensor(s), including basesensors 130 a and rotating sensors 130 b are shown in FIG. 1C and aredescribed by reference to that Figure. Regarding, FR module 122 b, inFIG. 1B, it is further noted that FR module 122 b may include facialrecognition software for interpreting image data received from imagesensor 122 e and/or cameras 138 b shown in FIG. 1C to be included amongrotating sensors 130 b of P/R sensor(s). By way of analogously, ORmodule 122 d may include object recognition software for interpretingimage data received from image sensor 122 e and/or cameras 138 b. By wayof further analogy, ASR module 122 c may include speech recognitionsoftware for determining which sounds sensed using one or moremicrophone(s) constitute speech by one or more of observers 117 a and117 b. Moreover, in some implementations, ASR module may be implementedto interpret speech by observer 117 a and/or observer 117 b.

It is also noted that the specific sensors and sensing modules shown tobe included among sensors 122 of sensor network 120 are merelyexemplary, and in other implementations, sensors 122 of sensor network120 may include more, or fewer, sensors than RFID reader 122 a, FRmodule 122 b, ASR module 122 c, OR module 122 d, image sensor 122 e, andP/R sensor(s) 130. RFID reader 122 a, FR module 122 b, ASR module 122 c,OR module 122 d, image sensor 122 e, and P/R sensor(s) 130 may beimplemented using any suitable sensors and software for those respectivefunctions, as known in the art. Microphone(s) 124 may include one ormore stationary and/or moving microphone(s). For example, stationarymicrophone(s) of microphone(s) 124 may be distributed in a 360° arraysurrounding base 140 to enhance directional sensing of sound, such asspeech, produced by one or more of observers 117 a and 117 b.

In some implementations, one or more moving microphone(s) ofmicrophone(s) 124 may rotate in synchronization with rotor 148 anddisplay screen 190. In those implementations, P/R sensor(s) 130 may beused in combination with microphone(s) 124 to identify the directionfrom which a sound sensed using microphone(s) 124 is received.

Image sensor 122 e may correspond to one or more sensors for obtainingvisual images of observers 117 a and 117 b, as well as the local venuein which multi-perspective image display system 100 and observers 117 aand 117 b are located. Image sensor 122 e may be implemented as one ormore stationary and/or rotating video cameras, for example.

As indicated in FIG. 1B, in some implementations, data from P/Rsensor(s) 130, and/or data generated by ADC 126 from sounds detected bymicrophone(s) 124 may be processed by localization module 128 toidentify the distance and/or direction of the respective sources of thesounds received by microphone(s) 124, such as observers 117 a and 117 b.In those implementations, the output from localization module 128 may beprovided to ASR module 122 c to enhance the performance of ASR module122 c in discriminating among environmental sounds, noise, andpurposeful speech by one or more of observers 117 a and 117 b.

FIG. 1C shows a more detailed exemplary implementation of P/R sensor(s)130, in FIG. 1B. As shown in FIG. 1C, P/R sensor(s) 130 can include oneor more base sensor(s) 130 a integrated with base 140, and one or morerotating sensor(s) 130 b integrated with display screen 190 andconfigured to spin with display screen 190.

According to the exemplary implementation shown in FIG. 1C, basesensor(s) 130 a may include one or more of infrared (IR) light-emittingdiode (LED) 132 a, magnet 134 a, visible light LED 136 a, and glyph orother visible marker 138 a, to name a few examples. As further shown inFIG. 1C, rotating sensor(s) 130 b may include one or more of IR receiver132 b for sensing IR LED 132 a, Hall effect sensor 134 b for sensingmagnet 134 a, photo diode 136 b for sensing visible light LED 136 a, andone or more camera(s) 138 b for sensing glyph or visible marker 138 a.In addition, rotating sensor(s) 130 b are shown to be coupled torotational tracking module 131.

It is noted that the distribution of features identified by referencenumbers 132 a, 134 a, 136 a, 138 a, 132 b, 134 b, 136 b, and 138 bbetween base sensor(s) 130 a and rotating sensor(s) 130 b is merelyexemplary. In another implementation, for example, the positions offeatures 132 a, 134 a, 136 a, 138 a, 132 b, 134 b, 136 b, and 138 b maybe reversed. That is to say, one or more of IR LED 132 a, magnet 134 a,visible light LED 136 a, and glyph or visible marker 138 a may beincluded as rotating sensor(s) 130 b, while one or more of IR receiver132 b, Hall effect sensor 134 b, photo diode 136 b, and camera(s) 138 bmay be included as base sensor(s) 130 a. It is further noted thatcamera(s) 138 b may include one or more still camera(s) and/or one ormore video camera(s), for example. Moreover, in some implementations,P/R sensor(s) 130 may be implemented as an encoder.

As indicated in FIG. 1C, in some implementations, data from one or moreof IR receiver 132 b, Hall effect sensor 134 b, photo diode 136 b, andcamera 138 b is processed by rotational tracking module 131 to identifythe rotational position of display screen 190 being tracked by P/Rsensor(s) 130 at any point in time. In those implementations, the outputfrom rotational tracking module 131 may be provided to controller 110 orsoftware code 108 to enhance the performance of multi-perspective imagedisplay system 100 in displaying perspectives 119 a and 119 b ofmulti-perspective image 118.

FIG. 2A shows a diagram of exemplary multi-perspective image displaysystem 200, according to another implementation. As shown in FIG. 2A,multi-perspective image display system 200 includes base 240 and displayscreen 290. Base 240 is shown to include motor 242, and to be situatedon surface 250, which may be a floor or any other substantiallyhorizontal surface. In addition, according to the exemplaryimplementation shown in FIG. 2A, multi-perspective image display system200 includes rotor 248 coupled to display screen 290.

Display screen 290 includes display surface 292 having optional privacyscreen 266 affixed thereon. Also shown in FIG. 2A are horizontal axis252 (hereinafter also “X axis 252”) substantially parallel to surface250, vertical axis 254 (hereinafter also “Z axis 254”) substantiallyperpendicular to surface 250, spin direction 256 of rotor 248 anddisplay screen 290, two-dimensional (2D) image 228 rendered on displayscreen 290, and perspective lines 2B-2B and 3-3.

Multi-perspective image display system 200 corresponds in general tomulti-perspective image display system 100, in FIG. 1A. As a result,multi-perspective image display system 200 may share any of thecharacteristics attributed to multi-perspective image display system 100by the present disclosure, and vice versa. In addition, rotor 248 andbase 240 including motor 242, correspond respectively in general torotor 148 and base 140 including motor 142, in FIG. 1A. Thus, rotor 248,motor 242, and base 240 may share any of the characteristics attributedto rotor 148, motor 142, and base 140 by the present disclosure, andvice versa. That is to say, although not explicitly shown in FIG. 2A,base 240 includes features corresponding respectively to motor controlcircuit 144 and MCU 146.

Moreover, display screen 290 including display surface 292, in FIG. 2A,corresponds in general to display screen 190 including display surface192, in FIG. 1A. Thus, display screen 290 may share any of thecharacteristics attributed to display screen 190 by the presentdisclosure, and vice versa. In other words, although not explicitlyshown in FIG. 2A, display screen 290 includes features correspondingrespectively to controller 110 having CPU 112, GPU 114, DSP 116, andsystem memory 106 storing software code 108. Furthermore, likemulti-perspective image display system 100, multi-perspective imagedisplay system 200 includes sensor network 120 bridging base 140/240 anddisplay screen 190/290.

In some implementations, display screen 190/290 may be a liquid-crystaldisplay (LCD) screen, for example, or an organic light-emitting diode(OLED) display screen. For example, when implemented as an LCD screen,display screen 190/290 may take the form of an in-plane switching (IPS)LCD screen or a twisted nematic field effect (TN) LCD screen. Moreover,in some implementations, display screen 190/290 may be provided by amobile communication device coupled to rotor 148/248, and configured tospin with display screen 190/290. For example, display screen 190/290may be part of a smartphone or a tablet computer.

In the exemplary implementations shown in FIGS. 1A and 2A, variousfeatures and/or techniques may be utilized to reduce flicker and/or blurof multi-perspective image 118 produced by display screen 190/290. Forexample, optional privacy screen 266 may be affixed to display surface192/292 of display screen 190/290 so as to restrict viewing of displayscreen 190/290 outside of a predetermined viewing angle. Such a privacyscreen may take the form of a louvered structure affixed to displayscreen 190/290, or to a privacy film covering display surface 192/292 ofdisplay screen 190/290.

FIG. 2B shows a side view of exemplary multi-perspective image displaysystem 100/200 along perspective lines 2B-2B in FIG. 2A, according toone implementation. It is noted that any features in FIG. 2B identifiedby reference numbers identical to those shown in FIG. 2A correspondrespectively to those previously identified features and share theirrespective characteristics, and vice versa. In addition to the featuresdescribed above by reference to FIG. 2A, FIG. 2B shows axis of rotation255 of rotor 148/248 and display screen 190/290, as well as horizontalaxis 253 (hereinafter also “Y axis 253”) normal to display surface192/292 and perpendicular to horizontal X axis 152/252 and vertical Zaxis 154/254 in FIGS. 1A and 2A.

As shown in FIG. 2B, display surface 192/292 of display screen 190/290may be situated on axis of rotation 255 of rotor 148/248 and displayscreen 190/290. For example, in some implementations, display surface192/292 may be precisely aligned so as to be on axis of rotation 255 andso as to be centered on axis of rotation 255.

Referring to FIGS. 1, 2A, and 2B in combination, display surface 192/292may be controlled by CPU 112 and/or GPU 114 of controller 110, whilerotor 148/248 coupled to display screen 190/290 is controlled by CPU 112of controller 110 and motor control circuit 144. CPU 112 of controller110 is configured to execute software code 108 to render 2D image 228 ondisplay screen 190/290 using GPU 114.

CPU 112 is further configured to execute software code 108 to utilizemotor control circuit 144 and motor 142/242 to spin rotor 148/248 anddisplay screen 190/290 about axis of rotation 255 parallel to displaysurface 192/292 of display screen 190/290 at a spin rate to generatemulti-perspective image 118 corresponding to 2D image 228. As a specificexample, rotor 148/248 and display screen 190/290 may have a spin ratein a range from approximately 900 rpm to approximately 3600 rpm, whichtranslates to a range of time intervals per rotation about axis ofrotation 255 from approximately sixty-seven milliseconds per rotation(67 ms/rotation) to approximately 17 ms/rotation. As a result of therotation of rotor 148/248 and display screen 190/290 as 2D image 228 isrendered on display screen 190/290, multi-perspective image 118 mayappear to be floating in space, and/or may appear to be a 3D imagecorresponding to 2D image 228.

It is noted that CPU 112 of controller 110 may execute software code 108to control motor 142/242 in order to spin rotor 148/248 and displayscreen 190/290 about axis of rotation 255 at a varying spin rate, or ata substantially constant predetermined spin rate. It is also noted thatspin direction 256 may be in either a counter clockwise direction withrespect to the plane of horizontal axes 152/252 and 253, as shown inFIG. 2A, or in a clockwise direction with respect to that plane.

In some implementations, CPU 112 of controller 110 may execute softwarecode 108 to use GPU 114 of controller 110 to change 2D image 228 asrotor 148/248 and display screen 190/290 spin, so as to generatemultiple perspectives 119 a and 119 b of multi-perspective image 118that are appropriate respectively to the locations of each of observers117 a and 117 b. For example, observer 117 a located so as to face afront side of multi-perspective image 118 and stationary at thatlocation might consistently view multi-perspective image 118 fromfrontal perspective 119 a. By contrast, observer 117 b located so as toface a backside of multi-perspective image 118, i.e., 180° apart fromthe perspective of observer 117 a, and stationary at that location mightconsistently view multi-perspective image 118 as if from rearperspective 119 b.

FIG. 3 shows a top view of image viewing environment 301 includingmulti-perspective image display system 300 including rotor 348 and base340 along perspective lines 3-3 in FIG. 2A. It is noted that displayscreen 190/290 and internal features of base 340 are not shown in FIG. 3in the interests of conceptual clarity.

As shown in FIG. 3, image viewing environment 301 also includes circle372 of exemplary locations 374 a, 374 b, 374 c, 374 d, 374 e, 374 f, 374g, and 374 h (hereinafter “locations 374 a-374 h”) from which to observemulti-perspective image 118, in FIG. 1A. Also shown in FIG. 3 areobserver 317 a viewing perspective 319 a of multi-perspective image 118,and observer 317 b viewing another perspective 319 b ofmulti-perspective image 118. It is noted that circle 372 includingexemplary locations 374 a-374 h for viewing different perspectives ofmulti-perspective image 118 is substantially concentric with rotor 348.

Multi-perspective image display system 300 including rotor 348 and base340 corresponds in general to multi-perspective image display system100/200 including rotor 148/248 and base 140/240 in FIGS. 1A, 2A, and2B. Thus, multi-perspective image display system 300, rotor 348, andbase 340 may share any of the characteristics attributed to respectivemulti-perspective image display system 100/200, rotor 148/248, and base140/240 by the present disclosure, and vice versa. In addition, observer317 a, observer 317 b, and perspectives 319 a and 319 b correspondrespectively in general to observer 317 a, observer 317 b, andrespective perspectives 119 a and 119 b, in FIG. 1A.

In one exemplary implementation, observer 117 a/317 a may be at location374 a corresponding to a zero crossing of circle 372, i.e., 0° or 360°(or zero or 2π radians) along the circumference of circle 372, asdetectable using sensor network 120. From that location, observer 117a/317 a may face a front side of multi-perspective image 118, forexample, and view multi-perspective image 118 displayed bymulti-perspective image display system 100/200/300 from frontalperspective 119 a/319 a. By contrast, observer 117 b/317 b located so asto face a backside of multi-perspective image 118 from location 374 e,i.e., a location 180° (π radians) apart from location 374 a of observer317 a/317 a, would view multi-perspective image 118 as if from backsideperspective 119 b/319 b. In other words, in an exemplary use case inwhich multi-perspective image 118 is observable from two locationscorresponding to locations 374 a and 374 e, multi-perspective imagedisplay system 100/200/300 may display two perspectives 119 a/319 a and119 b/319 b of multi-perspective image 118.

In other implementations, however, more perspectives ofmulti-perspective image 118 may be displayed. For example, in oneimplementation, circle 372 may include four locations for viewingmulti-perspective image 118 that are 90° (π/2 radians) apart withrespect to circle 372, e.g., locations 374 a, 374 c, 374 e, and 374 g.In that implementation, perspectives 119 a/319 a and 119 b/319 b mayonce again be respective frontal and backside perspectives ofmulti-perspective image 118, while the perspectives viewable fromlocations 374 c and 374 g may be opposing side views ofmulti-perspective image 118 (i.e. left and right side viewperspectives).

As another example, in implementations in which circle 372 includes sixlocations for viewing multi-perspective image 118, e.g., locations 374a-374 h, each of those locations may be 60° (π/3 radians) apart withrespect to circle 372. In that implementation, multi-perspective imagedisplay system 100/200/300 may be configured to display six distinctperspectives of multi-perspective image 118 that correspond respectivelyto locations 374 a-374 h. It should be understood, that with anincreasing spin rate and an increasing number of alternating anddistinct views (e.g. up to 360 distinct views), an up to 360°holographic view of multi-perspective image 118 may be achieved.

The functionality of multi-perspective image display system 100/200/300including base 140/240/340 and display screen 190/290 will be furtherdescribed by reference to FIG. 4. FIG. 4 shows flowchart 480 of anexemplary method for displaying multiple perspectives of an image usingillumination switching, according to one implementation. With respect tothe method outlined in FIG. 4, it is noted that certain details andfeatures have been left out of flowchart 480 in order not to obscure thediscussion of the inventive features in the present application.

Referring to FIG. 4 in combination with FIGS. 1A, 2A, 2B, and 3,flowchart 480 begins with causing motor 142/242 to spin display screen190/290, using rotor 148/248/348, about axis of rotation 255 at a spinrate (action 482). In some implementations, controller 110 may beconfigured to utilize motor control circuit 144 including MCU 146 tocause motor 142/242 to spin rotor 148/248/348 and display screen 190/290about axis of rotation 255 parallel to display surface 192/292 ofdisplay screen 190/290 at a predetermined spin rate, which may be in arange from approximately 900 rpm to approximately 3600 rpm, for example.Alternatively, in some implementations, CPU 112 of controller 110 may beconfigured to execute software code 108 to use motor control circuit 144to control motor 142/242 to spin rotor 148/248/348 and display screen190/290 about axis of rotation 255 at a predetermined spin rate.

According to various implementations of the present inventive concepts,the spin rate of rotor 148/248/348 and display screen 190/290 may dependin part on the frame rate of display screen 190/290. As known in theart, the term “frame rate” refers to the rate or frequency with which anew frame can be rendered on a display, expressed in frames per second(fps). Thus, frame rate is to be distinguished from refresh rate, whichis the rate or frequency with which the same frame can be redrawn on adisplay.

In addition, in some implementations, the spin rate of rotor 148/248/348and display screen 190/290 may depend in part on the response time ofdisplay screen 190/290. It is noted that, as defined in the presentapplication, the term “response time” refers to the time intervalrequired for a frame rendered by CPU 112 and/or GPU 114 of controller110 to be completely drawn on display surface 192/292 of display screen190/290. As known in the art, the response time of display screen190/290 may vary with the display technology used to implement displayscreen 190/290. For example, as noted above, in some implementations,display screen 190/290 may be an IPS LCD screen, which typicallyprovides excellent color range but a relatively slow response time.However, in other implementations, it may be advantageous or desirableto implement display screen 190/290 as a TN LCD screen having a fasterresponse time but providing an inferior color range when compared to anIPS LCD screen.

Flowchart 480 may continue with determining, based on the spin rate, anillumination on-time for an illumination source of display screen190/290 (action 484). In implementations in which display screen 190/290is an emissive display, the illumination source of display screen190/290 may be OLEDs themselves (e.g., AMOLED displays) or diffusedbacklighting layered behind an LCD display screen. Alternatively, insome implementations, display screen 190/290 may be implemented as areflective display screen, such as a projection screen, or may beimplemented as a normally emissive display screen utilized in reflectivemode. In implementations in which display screen 190/290 is reflectiveor being used in reflective mode, the illumination source of displayscreen 190/290 may be a frontlight, such as a projection lamp, forexample.

As defined for the purposes of the present application, the term“illumination on-time” of display screen 190/290 refers to the timeinterval during which the illumination source of display screen 190/290,e.g., backlight or frontlight, is switched on while rotor 148/248/348and display screen 190/290 spin. At times during the spinning of rotor148/248/348 and display screen 190/290 outside of the illuminationon-time interval, the illumination source of display screen 190/290 isswitched off.

Determination of the on-time for the illumination source of displayscreen 190/290 may be performed by controller 110. In someimplementations, CPU 112 of controller 110 may be configured to executesoftware code 108 to determine the on-time for the illumination sourceof display screen 190/290 based on the spin rate of rotor 148/248/348and display screen 190/290.

In some implementations, controller 110 may be configured to determinethe illumination on-time for the illumination source of display screen190/290 further based on a predetermined viewing angle for each ofperspectives 119 a/319 a and 119 b/319 b of multi-perspective image 118to be rendered on display screen 190/290. Moreover, in addition, oralternatively, controller 110 may be configured to determine theillumination on-time for the illumination source of display screen190/290 further based on the response time of display screen 190/290.

In implementations in which the illumination on-time for theillumination source of display screen 190/290 is determined based on apredetermined viewing angle for each of perspectives 119 a/319 a and 119b/319 b of multi-perspective image 118 and the response time of displayscreen 190/290, in addition to the spin rate, controller 110 may beconfigured to determine the illumination on time as:t _(on-time)=0.159*(Φ/V)−t _(response-time) +t _(offset)  (Equation 1)where Φ is the predetermined viewing angle expressed in radians, V isthe predetermined spin rate of rotor 148/248/348 and display screen190/290 expressed in Hz, t_(response-time) is the known displaytechnology's response time in seconds of display screen 190/290, andt_(offset) is the adjustment to account for spin rate variation ofdisplay screen 190/290.

It is noted that t_(offset) may be thought of as the “jitter estimate”of the spin rate, i.e., the variance of the actual spin rate of rotor148/248/348 and display screen 190/290 from the predetermined spin rateV, as measured or estimated via graphics rendering. As a result, in usecases in which the jitter estimate is de minimis, and may be ignored,the t_(offset) term may be omitted from Equation 1. Thus, according toEquation 1, the illumination on-time for the illumination source ofdisplay screen 190/290 may be determined based at least on a ratio ofthe predetermined viewing angle to the spin rate, minus the responsetime of display 190/290. It is noted that the spin rate V_(measured) maybe determined by controller 110 using P/R sensor(s) 130 of sensornetwork 120.

Flowchart 480 may continue with sequentially rendering each of multipleperspectives 119 a/319 a and 119 b/319 b of multi-perspective image 118on display screen 190/290 during each revolution of display screen190/290 about axis of rotation 255 (action 486). The sequentialrendering of each of multiple perspectives 119 a/319 a and 119 b/319 bof multi-perspective image 118 on display screen 190/290 may beperformed by controller 110. For example, controller 110 may utilize CPU112 and/or GPU 114 to sequentially render perspectives 119 a/319 a and119 b/319 b on display screen 190/290 during each revolution of displayscreen 190/290 about axis of rotation 255. Alternatively, in someimplementations, CPU 112 of controller 110 may execute software code 108to utilize GPU 114 to sequentially render perspectives 119 a/319 a and119 b/319 b on display screen 190/290 during each revolution of displayscreen 190/290 about axis of rotation 255.

In one implementation, each perspective 119 a/319 a and 119 b/319 b ofmulti-perspective image 118 may correspond to a virtual camera of avirtual world, such as provided by a game engine. For example, multipleperspectives 119 a/319 a and 119 b/319 b of multi-perspective image 118may be provided as though captured by a virtual camera revolving aroundmulti-perspective image display system 100/200/300 on circle 372 insynchronization with rotor 148/248/348 of multi-perspective imagedisplay system 100/200/300. As a result, in that implementation, CPU 112and/or GPU 114 of controller 110 may be configured to rendermulti-perspective image 118 so as to include virtual world imagerysynchronized with the respective real world perspectives of observers117 a/317 a and 117 b/317 b appropriate to their respective locations.

Flowchart 480 may conclude with strobing the illumination source ofdisplay screen 190/290 based on the determined illumination on-time todisplay perspectives 119 a/319 a and 119 b/319 b of multi-perspectiveimage 118, where the strobing is performed concurrently with thesequentially rendering of each of multiple perspectives 119 a/319 a and119 b/319 b of multi-perspective image 118 on display screen 190/290(action 488). Strobing of the illumination source of display screen190/290 may be performed by controller 110, through the selectiveswitching on and off of a backlight or frontlight illumination source ofdisplay screen 190/290, for example, as perspectives 119 a/319 a and 119b/319 b of multi-perspective image 118 are sequentially rendered ondisplay screen 190/290, and as rotor 148/248/348 and display screen190/290 spin.

FIG. 5A shows exemplary timing diagram 500A of illumination switchingfor two-perspective image display using a TN LCD screen, according toone implementation, while FIG. 5B shows exemplary timing diagram 500B ofillumination switching for two-perspective image display using an IPSLCD screen, according to another implementation.

Referring to FIG. 5A, the use case depicted in that figure correspondsto a spin rate of approximately 1800 rpm, or thirty hertz (30 Hz). Asshown in FIG. 5A, the relatively fast response time of a TN LCD screenprovides a relatively large viewing angle Φ of approximately ⅔π radians,or 120°, for each of two perspectives 119 a/319 a and 119 b/319 b ofmulti-perspective image 118.

Referring to FIG. 5B, by contrast, the relatively slow response time ofan IPS LCD screen reduces the viewing angle Φ for each of twoperspectives 119 a/319 a and 119 b/319 b of multi-perspective image 118to approximately

$\frac{\pi}{2}$radians, or 90°. Moreover, the slower response time of the IPS LCDscreen requires a reduced spin rate of approximately 900 rpm, or 15 Hz.

FIG. 6 shows diagram 600 illustrating the calculation of exemplary starttimes for illumination of a display as it spins, according to oneimplementation. The timing regime shown in FIG. 6 is implemented inorder to create a symmetric viewing effect for multiple perspectives“N”. For example, and as shown in FIG. 6, to display four symmetricviewing segments with a ten degree viewing angle, the start time, i.e.,the delay interval from the zero position before the start of the firstillumination on-time of a rotation is given by Equation 2 as follows:

$\begin{matrix}{t_{start} = {{\left( {\frac{2\pi}{N_{segments}} + \Phi_{{view}\text{-}{offset}}} \right)*\left( \frac{1}{V} \right)} - \left( \frac{t_{{on}\text{-}{time}}}{2} \right)}} & \left( {{Equation}\mspace{14mu} 2} \right)\end{matrix}$where Φ_(view-offset) is the shift of the center of the first viewingwindow from the zero position expressed in radians, V is thepredetermined spin rate of rotor 148/248/348 and display screen 190/290expressed in Hz, and t_(on-time) is the on-time of the illuminationsource of display screen 190/290 discussed above.

As noted above, in actual use, the spin rate of rotor 148/248/348 anddisplay screen 190/290 may vary. That is to say, the actual spin rateV_(measured) may include a predetermined desired spin rate and avariance from that predetermined spin rate. Consequently, in someimplementations, it may be advantageous or desirable formulti-perspective display system 100/200/300 to use controller 110 todetect the variance from the predetermined spin rate and adjust the spinrate to substantially match the predetermined spin rate using motor142/242.

However, in other implementations, multi-perspective display system100/200/300 may use controller 110 to detect the variance from thepredetermined spin rate and modify the on-time for the illuminationsource determined in action 484, based on the variance from thepredetermined spin rate, resulting in an adjusted illumination on-time.In those implementations, controller 110 may then strobe theillumination source of display screen 190/290 based on the adjustedillumination on-time while spinning the display screen at the spin rateincluding the variance from the predetermined spin rate.

It is noted that, in some implementations, it may be advantageous ordesirable to track the movement of one of observers 117 a/317 a or 117b/317 b relative to display screen 190/290 and to render perspective 119a/319 a or 119 b/319 b on display screen 190/290 so as to be viewable bythat observer from the same perspective at all locations. For example,where observer 117 a/317 a is the subject of the tracking, one or moreof camera(s) 138 b of sensor network 120/220 may be utilized todetermine the location of observer 117 a/317 a relative to displayscreen 190/290, i.e., the position of observer 117 a/317 a with respectto exemplary locations 374 a-374 h of circle 372.

It is further noted that as technologies advance such that renderingframe rates and display refresh rates increase, while display responsetimes decrease, the maximum number of perspectives 119 a/319 a and 119b/319 b can increase, and may increase substantially. As that progressin the technology occurs there will eventually be a limit in which asingle frame rendered per viewing angle or perspective will then berequired to be a blended frame of one or more closely adjacent viewswhen different observers 117 a/317 a and 117 b/317 b are located veryclose to one another, for example, standing side-by-side or located suchthat one observer is looking over the shoulder of the other observer.

Thus, the present application discloses systems and methods fordisplaying multiple perspectives for viewing a virtual image and/ormultiple scenes using a single display. By spinning a display screenupon which a 2D image is rendered, about an axis, the present displaysolution is capable of generating an apparently floating image that mayappear to be 3D. In addition, by rendering multiple perspectives of theimage on the display screen during each revolution of the display screenabout the axis, the present display solution enables observers atvarious locations to see different perspectives of the image. As aresult, the display solutions disclosed in the present applicationadvantageously enable an observer of the image to view a perspective ofthe image that is appropriate to the location of the observer.

From the above description it is manifest that various techniques can beused for implementing the concepts described in the present applicationwithout departing from the scope of those concepts. Moreover, while theconcepts have been described with specific reference to certainimplementations, a person of ordinary skill in the art would recognizethat changes can be made in form and detail without departing from thescope of those concepts. As such, the described implementations are tobe considered in all respects as illustrative and not restrictive. Itshould also be understood that the present application is not limited tothe particular implementations described herein, but manyrearrangements, modifications, and substitutions are possible withoutdeparting from the scope of the present disclosure.

What is claimed is:
 1. A multi-perspective image display systemcomprising: a motor configured to spin a rotor; a display screen coupledto the rotor, the display screen having an illumination source; acontroller configured to: cause the motor to spin the display screen,using the rotor, about an axis of rotation at a spin rate; while themotor is causing the display screen to spin, determine, based on thespin rate, an illumination on-time for strobing the illumination sourceof the display screen; sequentially render a plurality of perspectivesof an image, one after another, on the display screen during eachrevolution of the display screen about the axis of rotation; andconcurrently with sequentially rendering, for each of the plurality ofperspectives of the image, strobe the illumination source of the displayscreen for a period corresponding to the determined illumination on-timeto display each of the plurality of perspectives of the image during thedetermined illumination on-time on the display screen.
 2. Themulti-perspective image display system of claim 1, wherein the spin ratecomprises a predetermined spin rate and a variance from thepredetermined spin rate, and wherein the controller is furtherconfigured to: detect the variance from the predetermined spin rate; andadjust the spin rate to substantially match the predetermined spin rateusing the motor.
 3. The multi-perspective image display system of claim1, wherein the spin rate comprises a predetermined spin rate and avariance from the predetermined spin rate, and wherein the controller isfurther configured to: detect the variance from the predetermined spinrate; modify the determined on-time for the illumination source based onthe variance from the predetermined spin rate, resulting in an adjustedillumination on-time; and strobe the illumination source of the displayscreen based on the adjusted illumination on-time while spinning thedisplay at the spin rate using the motor and the rotor.
 4. Themulti-perspective image display system of claim 1, wherein the displayscreen is an emissive display screen and the illumination source is abacklight of the emissive display screen.
 5. The multi-perspective imagedisplay system of claim 4, wherein the display screen comprises anorganic light-emitting diode (OLED) display screen, an in-planeswitching (IPS) liquid-crystal display (LCD) screen, or a twistednematic field effect (TN) LCD screen.
 6. The multi-perspective imagedisplay system of claim 1, wherein the controller is configured todetermine the illumination on-time further based on a predeterminedviewing angle for each of the plurality of perspectives of the image tobe rendered on the display screen.
 7. The multi-perspective imagedisplay system of claim 6, wherein the controller is configured todetermine the illumination on-time further based on a response time ofthe display screen.
 8. The multi-perspective image display system ofclaim 7, wherein the controller is configured to determine theillumination on-time further based on a ratio of the predeterminedviewing angle to the spin rate, minus the response time of the displayscreen.
 9. The multi-perspective image display system of claim 1,wherein the controller is configured to determine the illuminationon-time further based on a response time of the display screen.
 10. Themulti-perspective image display system of claim 1, wherein the displayscreen is implemented as a reflective display screen and theillumination source is a frontlight.
 11. A method for use by amulti-perspective image display system including a controller, a motorconfigured to spin a rotor, and a display screen coupled to the rotor,the method comprising: causing, by the controller, motor to spin thedisplay screen, using the rotor, about an axis of rotation at a spinrate; while the motor is causing the display screen to spin,determining, by the controller, based on the spin rate, an illuminationon-time for strobing the illumination source of the display screen;sequentially rendering, by the controller, a plurality of perspectivesof an image, one after another, on the display screen during eachrevolution of the display screen about the axis of rotation; andconcurrently with sequentially rendering, for each of the plurality ofperspectives of the image, strobing, by the controller, the illuminationsource of the display screen for a period corresponding to thedetermined illumination on-time to display each of the plurality ofperspectives of the image during the determined illumination on-time onthe display screen.
 12. The method of claim 11, wherein the spin ratecomprises a predetermined spin rate and a variance from thepredetermined spin rate, the method further comprising: detecting, bythe controller, the variance from the predetermined spin rate; andadjusting the spin rate, by the controller using the motor, tosubstantially match the predetermined spin rate.
 13. The method of claim11, wherein the spin rate comprises a predetermined spin rate and avariance from the predetermined spin rate, the method furthercomprising: detecting, by the controller, the variance from thepredetermined spin rate; modifying, by the controller, the determinedon-time for the illumination source based on the variance from thepredetermined spin rate, resulting in an adjusted illumination on-time;and strobing, by the controller, the illumination source of the displayscreen based on the adjusted illumination on-time while spinning thedisplay at the spin rate using the motor and the rotor.
 14. The methodof claim 11, wherein the display screen is an emissive display screenand the illumination source is a backlight of the emissive displayscreen.
 15. The method of claim 14, wherein the display screen comprisesan organic light-emitting diode (OLED) display screen, an in-planeswitching (IPS) liquid-crystal display (LCD) screen, or a twistednematic field effect (TN) LCD screen.
 16. The method of claim 11,wherein the controller is configured to determine the illuminationon-time further based on a predetermined viewing angle for each of theplurality of perspectives of the image to be rendered on the displayscreen.
 17. The method of claim 16, wherein the controller is configuredto determine the illumination on-time further based on a response timeof the display screen.
 18. The method of claim 17, wherein thecontroller is configured to determine the illumination on-time furtherbased on a ratio of the predetermined viewing angle to the spin rate,minus the response time of the display screen.
 19. The method of claim11, wherein the controller is configured to determine the illuminationon-time further based on a response time of the display screen.
 20. Themethod of claim 11, wherein the display screen is implemented as areflective display screen and the illumination source is a frontlight.